An Effective Temperature Scale for Late‐M and L Dwarfs, from Resonance Absorption Lines of Csiand Rbi

• DOI: 10.1086/309095
• Publication Date: 2002-07-26T18:53:22Z
• Authors: Gibor Basri; Subhanjoy Mohanty; France Allard; Peter H. Hauschildt; Xavier Delfosse; Eduardo L. Martin; Thierry Forveille; Bertrand Goldman
• Keywords: Opacity; Line (geometry); Photosphere; Clearance; Effective temperature

We present Keck HIRES spectra of 6 late-M dwarfs and 11 L dwarfs. Our goal is to assign effective temperatures the objects using detailed atmospheric models fine analysis alkali resonance absorption lines CsI RbI. These yield mutually consistent results (+-150 K) when we use ``cleared-dust'' models, which account for removal refractory species from molecular states but do not include dust opacities. find a tendency RbI line imply slightly higher temperature, ascribe an incomplete treatment overlying The final adopt are based on fits alone, though support temperature sequence. This work, in combination with infrared, hints that these atmospheres has settled out high atmosphere deep photosphere. also derive radial rotational velocities all objects, finding previously discovered trend rapid rotation very low mass quite pervasive. To improve our analysis, there clear need better lists more understanding formation dynamics.